1. Department of Thoracic and Cardiovascular Surgery, Uijeongbu Eulgi Medical Center , Gyeonggi-do, Republic of Korea
2. Department of Thoracic and Cardiovascular Surgery, Asan Medical Center , Seoul, Republic of Korea
3. Department of Thoracic and Cardiovascular Surgery, Seoul National University Hospital , Seoul, Republic of Korea
4. Department of Thoracic and Cardiovascular Surgery, Samsung Medical Center , Seoul, Republic of Korea
5. Department of Thoracic and Cardiovascular Surgery, Yonsei University Hospital , Seoul, Republic of Korea